1. Technical Field
This application claims the benefit of Japanese Application No. 2009-069625, filed Mar. 23, 2009, all of which are hereby incorporated by reference.
The present invention relates to a serial printer and, more particularly, to control of a movement section of a printing head in logical seeking.
2. Related Art
In the related art, logical seeking is known as a technique of controlling a serial printer. Logical seeking refers to a technique of controlling the movement of a printing head and a printing medium according to a printing object so as to minimize a movement distance of the printing head. In addition, as an image processing technique of a scanner or a facsimile machine, a noise eliminating technique of eliminating noise corresponding to contamination, dust, or the like adhered to a manuscript sheet or a platen glass by image processing is known (for example, see JP-A-9-252386).
However, in the noise eliminating technique of the related art, noise which is not an isolated point may not be eliminated. If noise remains outside the range in which characters or photos are recorded on a manuscript medium, the printing head is pointlessly moved by logical seeking. That is, even when the noise eliminating technique of the related art and logical seeking are combined, an effect by which the time required for copying is shortened was limited.
As the invention for solving such a problem, it is conceivable to provide a technique that a horizontal band of pixels darker than the background color of a manuscript medium is derived in each band and the movement distance of the printing head is reduced according to a section in which a cumulative frequency from an edge of a band exceeds a predetermined threshold. Therefore, according to the invention associated with Japanese Patent Application No. 2008-36980, it is possible to reduce unnecessary movement of a printing head.